diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 829b26cd4549a4e07ccdf30ea87d902424ce737b..8397f6c9245158e8b3ff005bc58a419e4250169d 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -165,13 +165,17 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); struct xenvif_queue *queue = NULL; - unsigned int num_queues = vif->num_queues; + unsigned int num_queues; u16 index; struct xenvif_rx_cb *cb; BUG_ON(skb->dev != dev); - /* Drop the packet if queues are not set up */ + /* Drop the packet if queues are not set up. + * This handler should be called inside an RCU read section + * so we don't need to enter it here explicitly. + */ + num_queues = READ_ONCE(vif->num_queues); if (num_queues < 1) goto drop; @@ -222,18 +226,18 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); struct xenvif_queue *queue = NULL; + unsigned int num_queues; u64 rx_bytes = 0; u64 rx_packets = 0; u64 tx_bytes = 0; u64 tx_packets = 0; unsigned int index; - spin_lock(&vif->lock); - if (vif->queues == NULL) - goto out; + rcu_read_lock(); + num_queues = READ_ONCE(vif->num_queues); /* Aggregate tx and rx stats from each queue */ - for (index = 0; index < vif->num_queues; ++index) { + for (index = 0; index < num_queues; ++index) { queue = &vif->queues[index]; rx_bytes += queue->stats.rx_bytes; rx_packets += queue->stats.rx_packets; @@ -241,8 +245,7 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev) tx_packets += queue->stats.tx_packets; } -out: - spin_unlock(&vif->lock); + rcu_read_unlock(); vif->dev->stats.rx_bytes = rx_bytes; vif->dev->stats.rx_packets = rx_packets; @@ -378,10 +381,13 @@ static void xenvif_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 * data) { struct xenvif *vif = netdev_priv(dev); - unsigned int num_queues = vif->num_queues; + unsigned int num_queues; int i; unsigned int queue_index; + rcu_read_lock(); + num_queues = READ_ONCE(vif->num_queues); + for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) { unsigned long accum = 0; for (queue_index = 0; queue_index < num_queues; ++queue_index) { @@ -390,6 +396,8 @@ static void xenvif_get_ethtool_stats(struct net_device *dev, } data[i] = accum; } + + rcu_read_unlock(); } static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index f9bcf4a665bcaebc4f33bd28849cef2dadc4f698..602d408fa25e98a4651716b1390d2507bced4605 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -214,7 +214,7 @@ static void xenvif_fatal_tx_err(struct xenvif *vif) netdev_err(vif->dev, "fatal error; disabling device\n"); vif->disabled = true; /* Disable the vif from queue 0's kthread */ - if (vif->queues) + if (vif->num_queues) xenvif_kick_thread(&vif->queues[0]); } diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index d2d7cd9145b1c259a1f0f11414acca706e67bb7a..a56d3eab35dd650c4acfcda9e981c0220cba9e61 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -495,26 +495,26 @@ static void backend_disconnect(struct backend_info *be) struct xenvif *vif = be->vif; if (vif) { + unsigned int num_queues = vif->num_queues; unsigned int queue_index; - struct xenvif_queue *queues; xen_unregister_watchers(vif); #ifdef CONFIG_DEBUG_FS xenvif_debugfs_delif(vif); #endif /* CONFIG_DEBUG_FS */ xenvif_disconnect_data(vif); - for (queue_index = 0; - queue_index < vif->num_queues; - ++queue_index) - xenvif_deinit_queue(&vif->queues[queue_index]); - spin_lock(&vif->lock); - queues = vif->queues; + /* At this point some of the handlers may still be active + * so we need to have additional synchronization here. + */ vif->num_queues = 0; - vif->queues = NULL; - spin_unlock(&vif->lock); + synchronize_net(); - vfree(queues); + for (queue_index = 0; queue_index < num_queues; ++queue_index) + xenvif_deinit_queue(&vif->queues[queue_index]); + + vfree(vif->queues); + vif->queues = NULL; xenvif_disconnect_ctrl(vif); }